Liquid applicator and method of making same

Abstract: A liquid applicator which includes a liquid reservoir (2), a tip (5) for applying the liquid to an object, the tip having a rectangular cross-section and being held by a tip holder, a coupler (3) for connecting the tip holder to the liquid reservoir (2), the tip holder comprising an engager for the coupler; and the coupler (3) comprising means for receiving the engager of the tip holder such that the tip holder is slidably in the coupler.

Description: The present invention relates to a liquid applicator comprising: a liquid reservoir, a tip for applying a liquid contained in the liquid reservoir to an object, the tip having a rectangular cross-section and being held by a tip holder, and a coupler for connecting the tip holder to the liquid reservoir. Moreover, the invention relates to a method for producing such a liquid applicator. A liquid applicator of this kind which is usable as a writing tool, a paint applicator, a manicure applicator or a paste applicator and depending on its use may include ink, paint, correction ink, manicure or paste as the liquid, is known from GB-A-451 059, which represents the prior art as referred to in the preamble of each of claims 1 and 16. In this liquid applicator the tip holder holding the rectangular tip is screwed on the coupler, which in turn is fixedly secured to a liquid reservoir, so that the components have a defined, fixed orientation to one another. Fig. 16 shows another kind of a prior art liquid applicator, which will be described in the following: The illustrated pen includes a cylindrical writing tip 100 of plastics. Whether the tip is felt or plastic, the feature in common with the known applicators is that they use a cylindrial tip. The writing tip 100 is connected to a cylindrical core 101 through which ink is flown from a liquid reservoir to the writing tip 100. The core 101 is made of liquid permeable material such as porous substance and a textile bundle. The writing tip 100 and the core 101 are connected to each other by means of a tip holder 102 which consists of a thick trunk portion 105 and a thin branch portion 103. The trunk portion 105 includes an end portion having a large inside diameter enough to receive the core 101, and the branch portion 103 has an end portion having a large inside diameter big enough to receive the writing tip 100. The tip holder 102 is fabricated my machining (cutting). The writing tip 100 is held in the branch portion 103, and the core 101 is held in the trunk portion 105 of the tip holder 102. The core 101 secured to the tip holder 102 is inserted in a bore 108 of the coupler 106. The coupler 106 is secured to a liquid reservoir (not shown). Ink flows from the reservoir to the writing tip 100 through the bore 108. The flow of the ink is controlled by the valve (not shown). In use, the drafters push the writing tip 100 against paper. The core 101 is thrusted into the bore 108 and opens the valve (not shown) so as to alow ink to flow to the writing tip 100 through the bore 108. There are other proposals for liquid for liquid applicators using a valve in the reservoir; one is Japanese Utility Model Publication (allowed) No. 5-32235 and the other is Japanese Utility Model Laid-open Publication (Kokai) No. 1-84779 disclose liquid applicators having a valve. Another liquid applicator of this kind is known from EP-A-0 197 281. These proposed liquid applicators also use cylindrical tips. In general, cylindrical writing tips raise no problems in writing ordinary letters and draw ordinary lines, but they are inconvenient in drawing thick lines and/or painting out a relatively large area. Therefore, rectangular writing tips have recently thought out, wherein the rectangular tip" means a tip whose cross-section is flattened. The advantage of a rectangular tip is that the user can use the side faces ridges, and corner points of the tip unlike a cylindrical pointed tip. By using the corner points and ridges, thick and thin lines can be freely drawn, and a large area can be quickly painted out by using the side faces. In the liquid applicators using a valve, the tip must be pushed against paper to open the valve, but a problem arises when the rectangular tip is pushed, or if the drafter has habit of holding the applicator too strongly, in either case the tip is liable to a turning moment and tends to rotate. While writing letters or drawing lines, an unexpected rotation of the tip may spoil the regularity of lines and letters. Particularly in calligraphy the irregular handwriting may be fatal to the calligraphic beauty. Accordingly, it is the object of the present invention to provide a liquid applicator of the above mentioned kind using a rectangular tip, which does not involve the problem of irregular lines. According to the present invention this object is solved in that the tip holder is slidably but non-rotatably held in the coupler. Since the tip holder is non-rotatably held in the coupler, it may not rotate in use, so that a good line regularity may be obtained. The method for producing such liquid applicator comprises the steps of: fabricating a liquid reservoir, forming a coupler including ridges produced axially on and along the inside wall thereof; forming a tip having a rectangular cross-section; forming a cylindrical tip holder; flattening an end portion of the tip holder thereby enabling the end portion to expand side-ways; connecting the coupler to the liquid reservoir; and connecting the tip holder to the coupler with the expanded end portion thereof being engaged with the ridges of the coupler; so that the tip holder is slidably but non-rotatably held in the coupler. Figure 1 is a perspective view showing an example of the liquid applicators embodying the present invention; Figure 2 is a cross-sectional view showing a liquid applicator produced according to the present invention; Figure 3A is an exploded perspective view showing a tip unit incorporated in the liquid applicator shown in Figure 1; Figure 3B is an exploded perspective view showing a tip unit an a coupler connectable to a liquid reservoir in the liquid applicator shown in Figure 1; Figure 4 is a partially cross-sectional view on an larger scale showing the tip portion of the liquid application shown in Figure 2; Figure 5 is a partially cross-sectional view on an larger scale showing the side portion of the liquid application shown in Figure 4; Figure 6 is a fragmentary view taken in the direction of the arrow (A) in Figure 5; Figure 7 is a fragmentary plan view showing a modified version; Figure 8 is a fragmentary plan view showing another modified version; Figure 9 is a fragmentary plan view showing a further modified version; Figure 10A is an exploded perspective view showing a tip unit incorporated in a first modified version of the liquid applicator embodying the present invention; Figure 10B is an exploded perspective view showing a main portion of the liquid applicator shown in Figure 10A; Figure 11A is an exploded perspective view showing a tip unit incorporated in a second modified version of the liquid applicator embodying the present invention; Figure 11B is an exploded perspective view showing a main portion of the liquid applicator shown in Figure 11A: Figure 12A is an exploded perspective view showing a tip unit incorporated in a third modified version of the liquid applicator embodying the present invention; Figure 12B is an exploded perspective view showing a main portion of the liquid applicator shown in Figure 12A; Figure 13A is an exploded perspective view showing a tip unit incorporated in a fourth modified version of the liquid applicator embodying the present invention; Figure 13B is an exploded perspective view showing a main portion of the liquid applicator shown in Figure 13A: Figure 14 is a cross-sectional view showing a totally modified version of the liquid applicator embodying the present invention; Figure 15A is an exploded perspective view showing a tip unit incorporated in a fifth modified version of the liquid applicator embodying the present invention; Figure 15B is an exploded perspective view showing a main portion of the liquid applicator shown in Figure 15A: and Figure 16 is a perspective view showing a main portion of a known liquid applicator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to Figures 1 and 2, the exemplary liquid applicator 1 includes a liquid reservoir 2, a coupler 3, a tip 5, and a cap 4. The liquid reservoir 2 is made of aluminum, stainless steel, plastics or glass in a known manner such as deep drawing, extrusion, blowing, or injection. The reservoir 2 can hold not only ink but also paste, manicure, and the like, as the case may be. The liquid reservoir 2 is provided with a valve 6 made of plastics which includes a valve body 10, a valve seat 8, and a cylindrical frame 9. The seat 8 has a throat (restricted portion) 13 which passes outside of the reservoir 2. The frame 9 which is the frame unit adhering to the opening portion of the reservoir 2 is provided with openings (not shown) through which the liquid is allowed to come in and go out of the reservoir 2. The frame 9 has an opening 15 in the bottom. The valve body 10 has thick center portion, an abutment head 17 at one end and a guide portion 18 at the other end. The valve 6 is provided with the space for insertion of the valve by the seat 8 and frame 9. In this space, there is the valve body 10. The valve body 10 is movable up and down along and within the seat 8 and frame 9, with the abutment head 17 passing through the throat 13 and the guide portion 18 passing through the opening 15 at the bottom. The valve body 10 is normally biased by a spring 12 toward the valve seat 8 so as to close the throat 13. When the guide portion 18 of the valve body 10 is biased toward the reservoir 2, the tip is pushed against paper, thereby causing the abutment head 17 to withdraw against the spring 12 Thus the throat 13 is freed from the valve seat 8. The coupler 3, designed to close the reservoir 2, has an opening 19 whose inside wall has ridges 20 extending along the coupler 3 with grooves 28 there between. Each ridge 20 has a semi-circular cross-section. The number of the ridges 20 is optional; in the illustrated embodiment, four ridges are provided. An imaginary circle defined by the tops of the ridges 20 is slightly larger than the outside diameter of a trunk portion 27 of a tip holder 23 so that the tip holder 23 can pass through the opening 19 of the coupler 3. The coupler 3 is made of polypropylene by injection molding. The exemplary liquid applicator 1 is provided with a tip unit 5 which, in addition to the tip holder 27 referred to above, includes a tip 21, a core 22 and a tip holder 23. The tip 21 has a rectangular cross-section, and is made of liquid permeable synthetic resin such as polyacetal. Liquid permeability can be effected by providing the tip 21 with multiple tiny grooves or bores produced axially or making it with material having tiny grooves or bores there through. The liquid such as ink can permeate through the grooves or bores and reach the tip 21. Such grooves can be formed as narrow slits throughout its entire length. One method is to expand a material having bores so that the diameter of each bore is fully reduced. The core 22 is made of porous plastics or of a fibrous bundle in the form of a bar. The tip holder 23 is made of brass in the form of a cylinder throughout the length as shown in Figure 3A, and has an inside diameter enough to tightly accept the core 22. The tip holder 23 is usually made in a known manner such as by machining(cutting), drawing or rolling. The tip 21, the core 22 and the tip holder 23 are connected by following process so as to form the tip unit 5. First, the tip 21 is inserted in an end portion 24 of the tip holder 23, and then the end portion 24 is flattened as by pressing or crushing in the directions of arrows B in Figure 3A so as to secure the tip 21 in the flattened end portion 24. The flattened end portion 24 is expanded sideways to form an expanded end portion 25 extending beyond the body portion 27. In the liquid applicator 1 of the present invention the tip 21 and the tip holder 23 are connected by pressing the end tip holder 23. Therefore a cross-section of the trunk 27 of the tip holder 23 has the shape of a circle. But flattened end portion 24 has the pressed shape. To put it concretely, as shown in Figure 3B and 6 as the flattened end portion 24 is stuck together the tip 21. Therefore, the tip 21 is flatter than the other trunk portion 27. On the other hand, the fattened end portion 24 has a wider width than tip 21 and has a more ridged shape than the truck portion 27 of tip holder 23. The expanded end portion 25 functions as an engager for connection to the coupler 3. Then, the core 22 is pressed into the opposite end of the tip holder 23 until it comes into abutment with the tip 21 within the tip holder 23. In assembling the liquid applicator 1, the coupler 3 is connected to the top end of the reservoir 2, and as shown in Figure 3B, the tip unit 5 is inserted into the opening 19 of the coupler 3, the core 22 of the tip unit 5 is first inserted in the coupler 3 until it comes into engagement with the abutment head 17. At this stage, the expanded end portion 25 (engager) of the tip holder 23 engages the ridges 20 of the coupler 3, that is, since the extended end portion 25 of the flattered end portion 24 of the tip holder 23 is protruded beyond the trunk portion 27 of the tip holder 23, the expanded end portion 25 is received in the grooves 28 between the ridges 20. The ridges 20 function just like guide rails for the sliding tip holder 23 within the coupler 3. In this way it is ensured that the tip unit 5 is prevented from rotation by the ridges 20 but allowed to slide in and along the opening 19. The coupler 3 is secured to the reservoir 2, and the tip unit 5 is inserted into the opening 19 of the coupler 3. In this way the tip unit 5 is coupled to the reservoir 2 through the coupler 3 where the core 22 comes into abutment with the abutment head 17 so as to complete a communicable passage of the liquid from the reservoir 2 to the tip 21. The tip unit 5 ( the extended end portion 25 ) is slidably held in the coupler 3 without the possibility of rotation. In use for calligraphy, for example, the drafter pushes the tip 21 against paper. The tip unit 5 is pushed into the coupler 3 with the expanded portion 25 being slidably held in the opening 19. In pushing the tip 21, the core 22 is withdrawn and brought into abutment with the abutment head 17 of the valve body 10. Thus, the throat 13 is set free from the seat 8, thereby enabling the liquid to flow from the reservoir 2 and be absorbed in the core 22. Since the tip 21 is sheathed by the tip holder 23, it is protected against buckling under the force with which the tip 21 is pushed against paper. Preferably, the core 22 is covered with porous material around the periphery so as to absorb the liquid and retain any liquid surplus. As shown in Figure 6, the grooves 28 in which the expanded end portion 25 of the tip holder 23 is absent function as air passages, thereby facilitating the flow of the liquid. While the drafter uses the applicator, the tip can be tilted or used on the other side so as to use various writing areas of the rectangular tip. The manipulation otherwise would cause a turning moment upon the tip 21 but since the tip holder 23 is nonrotatably held in the coupler 3 by engagement of the expanded end portion 25 with the ridges 20, the tip 21 is prevented from rotation. In this way, the drafter can freely manipulate the tip 21 in accordance with the object to be written and/drawn. In addition, the tip 21 is protected by the tip holder 23 against breaking or buckling under any external force acting on the tip 21 so that the liquid passageways inside the tip 21 and core 22 are protected against becoming suffocated because of crushing. Thus the tip 21 can continuously receive the supply of the liquid. A relatively long tip 21 can be used under the protection provided by the tip holder 23, and if required, the tip may be projected longer than otherwise so as to avoid conflict between the coupler and the paper. Referring to Figures 6, 7, and 8, the relationship between the the expanded end portion 25 and the coupler 3 will be described: In Figure 6, the tip 21 is held in the tip holder 23 with spaces 29 on opposite sides and with the top and bottom sides of the tip 21 kept in contact with the inside wall of the tip holder 23. Figure 7 shows a modification in which a tip holder 34 has a bent portion 35 in which the tip holder 34 keeps contact with a tip 33, with the opposite sides of the tip 33 kept in full contact with the inside wall of the tip holder 34. Figure 8 shows another modification in which a tip 37 is held in a tip holder 36 with all sides thereof kept in contact with the inside wall of the tip holder 36. It will be understood from Figures 6 to 8 that the present invention allows various types of tips to be carried on the tip holder. There can be a way to flatter the tip holder after having inserted the tip 21. It is of course possible to shape the tip holder in various forms in accordance with those of the tip. The tip holder is not limited to a type having the same diameter throughout the length but it can be shaped to have a trunk portion having a large diameter and a thin portion having a small diameter as shown in Figure 16. The end portion of the tip holder 23 can be flattened in various manners; one example is shown in Figure 10B in which the opposite ends of a tip holder 30 are flattened. The rear end portion of the tip holder 30 opposite to the coupler 3 is expanded sideways as by pressing in the directions indicated by the arrows C, and the front end portions are pressed in the four directions indicated by the arrows D. The expanded end portions 31 are inserted in the opening 19 of the coupler 3 and engaged with the ridges 20 thereof. There can be a way made for projections and jutting out ridges around the hollow to make just the engager. Alternatively, it is possible to provide the tip holder with grooves axially produced, and provide the coupler with projections engageable in these grooves of the tip holder. Furthermore, as shown in Figure 9, it is also possible to shape the top end portion of the tip holder in a polygonal form and shape the opening 43 of the coupler 41 in the same polygonal form so as to enable the tip holder and the coupler to match each other. In the illustrated embodiments the tips 21, 33, and 37 and the core 22 are connected to each other through the tip holders 23, 34 and 36, respectively. The tips are securely held by pressing the end portions of the tip holders. The tip holders can be replaced by a joint of plastics, which will be described by reference to Figures 11A and 11B wherein like numerals refer to like and corresponding parts throughout the drawings and the description thereof will be omitted for simplicity: The liquid applicator 50 has a tip unit 51 which has a same structure from the tip unit 5 used in the first example. The reservoir 2 is a vessel made of aluminium and such, and has valve 6 inside. (See figure 2) Coupler 3 is a lid to valve body 10. And 4 ridges are made inside the opening 19. A notable feature of the liquid applicator 50 is in the structure of a tip unit 51 which consists of a connector 53 connecting a tip 21 and a core 22, both of which are the same as those used in the aforementioned examples. The connector 53 is made of plastics such as polypropylene by an injection molding method, and is provided with a frame member 56 secured to a cylindrical body portion 55 having an inside diameter adapted to accept the outside diameter of the core 22. The tip 21 is brought into contact with the core 22 within the tip holder 53. The frame member 56 is a rectangle and extends sideways beyond the diameter of the body portion 55. The reference numeral 57 denotes the opposite end portions of the frame member 56, which function as an engager for the coupler 3. The tip unit 51 used on this example consists of the tip 21 pushed into the frame member 56 of the connecter 53 . Core 22 is pushed into the cylindrical portion 55. One end of the tip 21 inside the connecter 53 goes through frame member 56 then, comes up to the cylindrical portion 55. Inside the connecter 53, the tip 21 touches the core 22. When the tip unit 51 is inserted into the coupler 3, the end portions 57 are engaged with the ridges 20, thereby preventing the tip unit 51 from rotation within the coupler 3. Referring to Figures 12A, 12B, 13A, and 13B, another modified version of the embodiment will be described, wherein like numerals refer to like and corresponding parts throughout the drawings and the description thereof will be omitted for simplicity: This example is different from the embodiments described above, in that no core is used. Instead of the core, a long tip 62 is used which is held by a tip holder 23 having the same structure as the tip holder referred to in the first and second examples. The tip 62 is passed through the tip holder 23, and one end portion of the tip holder is flattened in the same manner as described above, so as to hold the tip 62. One end of the tip 62 is used as a writing tool, and the other end is brought into abutment with the abutment head 17 of the valve 10 in the coupler 3. The tip holder 23 carrying the tip 62 is slidable in and along the opening 19 of the coupler while the expanded portion 25 are engaged with the ridges 20, thereby preventing the tip from rotation. In flattening the end portion of the tip holder 23, another method can be applied as shown in Figures 13A and 13B. By this method the tip holder 23 is flattened in its whole surface so as to hold the long tip 62. A tip unit including the wholly flattened tip holder 23 and the tip 62 is indicated by the reference numeral 64. Like the tip unit 64 shown in Figure 13A and 13B, the tip unit 38 shown in Figure 10A and 10B, it is possible to engage the engager of tip unit on to other unit other than the coupler about the engager being made inside the coupler's fitting side. A way to engage the engager of the tip unit other than the coupler is shown in Figure 14. Referring to Figure 14, the exemplary liquid applicator 65 includes a valve seat 66 extending along the inside wall of the coupler 3 and terminating near the opening 19, and having four ridges 67 on its inside wall so as to receive the tip holder in diametrically opposite grooves between the ridges 67, as shown in Figures 6, 7, and 8. As is evident from the foregoing description, the major feature of the liquid applicator according to the present invention is that the ridges 20 are provided to produce grooves 28 which receive the tip or tip holder, thereby preventing the tip from being rotated and becoming buckled under an excessive load. This ridge-groove structure of the coupler is applicable to liquid applicators having any shape of tip or pen. In the writing tool above mentioned using Figure 1 to 13 explanations of the coupler have been mainly on the structure which consists a engager which is a opening with 4 ridges. About the liquid applicator 65 shown in Figure 14 made of 4 ridge 67's in valve seat 66 functions as an engager have the cross-section shape of openings of couplers can of course be altered according to the shape of tip holder. But 4 ridges made already explained is most preferable. The reason is that with 4 ridge 20's structure, the column part is held firm by 4 ridges, therefore, makes the tip holder possible to insert movablely in the axis direction even though the normal tip holder no having the engager. Figures 15A and 15B shows a modified version of the tip used in the liquid applicator according to the present invention. The illustrated tip consists of a rectangular portion used as a tip, and a cylindrical portion which is capable of fully matching the abutment head 17 because both are circular in cross-section. As is evident from the foregoing description, according to the present invention the turning moment exerting on the tip is absorbed in the coupler, thereby ensuring that the tip is prevented from rotation likely to occur when the user manipulates the applicator. In addition, the tip is protected against breaking or buckling under external force applied to the applicator. It is understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the scope of the appended claims.

Claims: Liquid applicator comprising: a liquid reservoir (2), a tip (21, 33, 37, 62) for applying a liquid contained in the liquid reservoir (2) to an object, the tip (21, 33, 37, 62) having a rectangular cross-section and being held by a tip holder (23, 30, 34, 38, 53), and a coupler (3, 41) for connecting the tip holder (23, 30, 34, 38, 53) to the liquid reservoir (2), characterized in that the tip holder (23, 30, 34, 38, 53) is slidably but non-rotatably held in the coupler (3, 41). Liquid applicator according to claim 1, characterized in that the tip holder (23, 30, 34, 38, 53) comprises a flattened end portion (24, 25, 31, 57), which forms an engager for the coupler (3, 41). Liquid applicator according to claim 2, characterized in that the flattened end portion (24, 25) of the tip holder (23, 30, 34, 38, 53) is the front end portion, where the tip (21, 33, 37, 62) is held. Liquid applicator according to any preceding claim, characterized in that a valve (6) is provided in the liquid reservoir (2), wherein the valve (6) is openable when the tip (21, 33, 37, 62) is pushed. Liquid applicator according to claim 4, characterized in that a core (22) is connected to the end of the tip holder (23, 30, 34, 38, 53) opposite to the tip (21, 33, 37, 62), wherein the core (22) is engageable with the valve (6) so as to open the reservoir (2) when the tip (21, 33, 37, 62) is pushed. Liquid applicator according to claim 4 or 5, characterized in that the valve (6) comprises a receiver for receiving an engager of the tip holder (23, 30, 34, 38, 53) thereby ensuring that the tip holder (23, 30, 34, 38, 53) is slidable but non-rotatable in and along the coupler (3, 41). Liquid applicator according to any preceding claim, wherein the coupler (3) comprises means (20, 67) for non-ratatably receiving the engager of the tip holder (23, 30, 34, 38, 53). Liquid applicator according to claim 7, characterized in that the means for receiving the engager of the tip holder (23, 30, 34, 38, 53) comprises ridges (20, 67) produced axially on and along the inside wall of the coupler (3). Liquid applicator according to claim 8, wherein the means for receiving the engager comprise four ridges (20, 67). Liquid applicator according to any preceding claim, wherein the tip (21, 33, 37, 62) is long enough to pass through the tip holder (23, 30, 34, 38, 53). Liquid applicator according to calim 10, wherein the tip holder (23) is flattened in its entire surface area. Liquid applicator according to claim 6 or 7, characterized in that the tip (21, 33, 37, 62) comprises a first portion (24, 25) having a rectangular cross-section and a second portion having a cylindrical cross-section. Liquid applicator according to any preceding claim, wherein a core (2) is inserted into the tip holder (23, 30, 34, 38, 53) at the end opposite of the tip (21). Liquid applicator according to claim 13, wherein the tip (21, 33, 37, 62), the tip holder (23, 30, 34, 38, 53) and the core (22) form a tip unit (5, 38, 51, 64). Liquid applicator according to any preceding claim, wherein the tip holder (23, 30, 34, 38, 53) is provided by a joint made of plastics. A method for producing a liquid applicator comprising the steps of: fabricating a liquid reservoir (2), forming a coupler (3, 41) including ridges (20, 67) produced axially on and along the inside wall thereof; forming a tip (21, 33, 37, 62) having a rectangular cross-section; forming a cylindrical tip holder (23, 30, 34, 38, 53); flattening an end portion (24, 25, 31, 57) of the tip holder (23, 30, 34, 38, 53) thereby enabling the end portion (24, 25) to expand side-ways; connecting the coupler (3, 41) to the liquid reservoir (2); and connecting the tip holder (23, 30, 34, 38, 53) to the coupler (3, 41) with the expanded end portion (24, 25) thereof being engaged with the ridges (20, 67) of the coupler (3, 41); so that the tip holder (23, 30, 34, 38, 53) is slidably but non-rotatably held in the coupler (3, 41). Method according to claim 16, further comprising the steps of fabricating a core (22) and inserting the core (22) in the end of the tip holder (23, 30, 34, 38, 53) opposite to the flattened end. Method according to claim 16 or 17, further comprising the step of disposing a valve (6) in the liquid reservoir (2) actuable by pushing the tip (21, 33, 37, 62).

Inventors: KOBAYASHI NOBUAKI, KOBAYASHI, NOBUAKI
Applicants: SAKURA COLOR PROD CORP, SAKURA COLOR PRODUCTS CORPORATION
Application year: 1994
Main classification: B05C17
IPC codes: B43K5, B43K8, B05C17